/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/

#ifndef itkFastMarchingImageToNodePairContainerAdaptor_hxx
#define itkFastMarchingImageToNodePairContainerAdaptor_hxx

#include "itkMath.h"
#include "itkImageRegionConstIteratorWithIndex.h"

namespace itk
{

template <typename TInput, typename TOutput, typename TImage>
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::FastMarchingImageToNodePairContainerAdaptor()
  : m_AliveImage(nullptr)
  , m_TrialImage(nullptr)
  , m_ForbiddenImage(nullptr)
  , m_AlivePoints(nullptr)
  , m_TrialPoints(nullptr)
  , m_ForbiddenPoints(nullptr)
  , m_AliveValue(OutputPixelType{})
  , m_TrialValue(OutputPixelType{})
{}

template <typename TInput, typename TOutput, typename TImage>
void
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::SetAliveImage(const ImageType * iImage)
{
  m_AliveImage = iImage;
}

template <typename TInput, typename TOutput, typename TImage>
void
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::SetTrialImage(const ImageType * iImage)
{
  m_TrialImage = iImage;
}

template <typename TInput, typename TOutput, typename TImage>
void
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::SetForbiddenImage(const ImageType * iImage)
{
  m_ForbiddenImage = iImage;
}

template <typename TInput, typename TOutput, typename TImage>
auto
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::GetAlivePoints() -> NodePairContainerType *
{
  return m_AlivePoints.GetPointer();
}

template <typename TInput, typename TOutput, typename TImage>
auto
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::GetTrialPoints() -> NodePairContainerType *
{
  return m_TrialPoints.GetPointer();
}

template <typename TInput, typename TOutput, typename TImage>
auto
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::GetForbiddenPoints() -> NodePairContainerType *
{
  return m_ForbiddenPoints.GetPointer();
}

template <typename TInput, typename TOutput, typename TImage>
void
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::Update()
{
  this->GenerateData();
}

template <typename TInput, typename TOutput, typename TImage>
void
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::GenerateData()
{
  bool is_ok = false;

  if (m_AliveImage.IsNotNull())
  {
    SetPointsFromImage(m_AliveImage, Traits::Alive, m_AliveValue);
    is_ok = true;
  }

  if (m_TrialImage.IsNotNull())
  {
    SetPointsFromImage(m_TrialImage, Traits::InitialTrial, m_TrialValue);
    is_ok = true;
  }

  if (m_ForbiddenImage.IsNotNull())
  {
    SetPointsFromImage(m_ForbiddenImage, Traits::Forbidden, OutputPixelType{});
    is_ok = true;
  }

  if (!is_ok)
  {
    itkWarningMacro("no input image provided");
  }
}

template <typename TInput, typename TOutput, typename TImage>
void
FastMarchingImageToNodePairContainerAdaptor<TInput, TOutput, TImage>::SetPointsFromImage(const ImageType *       image,
                                                                                         const LabelType &       iLabel,
                                                                                         const OutputPixelType & iValue)
{
  if (iLabel == Traits::Alive || iLabel == Traits::InitialTrial || iLabel == Traits::Forbidden)
  {
    const NodePairContainerPointer nodes = NodePairContainerType::New();

    using IteratorType = ImageRegionConstIteratorWithIndex<ImageType>;
    IteratorType it(image, image->GetBufferedRegion());

    if (iLabel == Traits::Alive || iLabel == Traits::InitialTrial ||
        (iLabel == Traits::Forbidden && !m_IsForbiddenImageBinaryMask))
    {
      // Walk image
      for (it.GoToBegin(); !it.IsAtEnd(); ++it)
      {
        // Test if index value is greater than zero, if so add the node
        if (Math::NotAlmostEquals(it.Get(), ImagePixelType{}))
        {
          nodes->push_back(NodePairType(it.GetIndex(), iValue));
        } // end if image iterator > zero
      } // end for each pixel
    }
    else
    {
      for (it.GoToBegin(); !it.IsAtEnd(); ++it)
      {
        // Test if index value is greater than zero, if so add the node
        if (Math::AlmostEquals(it.Get(), ImagePixelType{}))
        {
          nodes->push_back(NodePairType(it.GetIndex(), iValue));
        } // end if image iterator > zero
      } // end for each pixel
    }

    switch (iLabel)
    {
      case Traits::Alive:
        m_AlivePoints = nodes;
        break;
      case Traits::InitialTrial:
        m_TrialPoints = nodes;
        break;
      case Traits::Forbidden:
        m_ForbiddenPoints = nodes;
        break;
      default:
        break;
    }
  }
}


} // namespace itk

#endif // itkFastMarchingImageToNodePairContainerAdaptor_hxx
